package org.bouncycastle.asn1.pkcs;

import java.math.BigInteger;

import org.bouncycastle.asn1.ASN1EncodableVector;
import org.bouncycastle.asn1.ASN1OctetString;
import org.bouncycastle.asn1.ASN1Sequence;
import org.bouncycastle.asn1.DEREncodable;
import org.bouncycastle.asn1.DERInteger;
import org.bouncycastle.asn1.DERObject;
import org.bouncycastle.asn1.DEROctetString;
import org.bouncycastle.asn1.DERSequence;
import org.bouncycastle.asn1.x509.DigestInfo;

public class MacData implements DEREncodable {
    DigestInfo digInfo;
    byte[] salt;
    BigInteger iterationCount;

    public static MacData getInstance(Object obj) {
        if (obj instanceof MacData) {
            return (MacData) obj;
        } else if (obj instanceof ASN1Sequence) {
            return new MacData((ASN1Sequence) obj);
        }

        throw new IllegalArgumentException("unknown object in factory");
    }

    public MacData(ASN1Sequence seq) {
        this.digInfo = DigestInfo.getInstance(seq.getObjectAt(0));

        this.salt = ((ASN1OctetString) seq.getObjectAt(1)).getOctets();

        if (seq.size() == 3) {
            this.iterationCount = ((DERInteger) seq.getObjectAt(2)).getValue();
        } else {
            this.iterationCount = BigInteger.valueOf(1);
        }
    }

    public MacData(DigestInfo digInfo, byte[] salt, int iterationCount) {
        this.digInfo = digInfo;
        this.salt = salt;
        this.iterationCount = BigInteger.valueOf(iterationCount);
    }

    public DigestInfo getMac() {
        return digInfo;
    }

    public byte[] getSalt() {
        return salt;
    }

    public BigInteger getIterationCount() {
        return iterationCount;
    }

    public DERObject getDERObject() {
        ASN1EncodableVector v = new ASN1EncodableVector();

        v.add(digInfo);
        v.add(new DEROctetString(salt));
        v.add(new DERInteger(iterationCount));

        return new DERSequence(v);
    }
}
